Alumino solder



Patented Au 23, 1927.

UNITED STATES 1,640,161 PATENT OFFICE.

BA-TI T0311, 01'- KAILAKURAGOBI, JAPAN- ALUIINO SOLDIER.

No Drawing.

This invention relates to an alloy for alumino-solder which contains 20-70% of zinc, 20-70% of tin, 5-35% of lead, 13-50% of cadmium, 1-5% of tin phosphide and 5 1-5% of magnesium; and its object is to obtain an excellent alloy for soldering an aluminium alloy (mainly duralumin) with the same or another aluminium alloy; metallic aluminium with metallic or an aluminium alloy; metallic aluminium with any any other metal etc. in an easy and safe manner sothat the joints are either protected from chemical action in contact with air or water or strongly resistable against the 15 breakln action by accidental or other external orces.

Alumino-solder according to this invention contains the following constituents:

The preparation of the new soldering allo may be as follows:

eat a definite quantity of tin at 230 C.

1 in a graphite crucible usm a blast furnace and whenfused, add a de nite quantity of .lead and ti'nC'pho hide and heat the mixture up to 330 en add a required uantity of cadmium, and lastly add zinc an mag- 36 nesium, the heating being continued at420 C. until all the contents are perfectly fused. Then pour the fused alloy into a metallic mould without any flux, and make the fused mass solidify rapidly by pouring. cold water 4 over it when he 'nning to cool.

The method 0 using the aluminium solder thus obtained is the same as that in usual solder. For instance, a soldering iron somewhat larger than that of the usual dimen- 5 sion, is employed after the surfaces to be joined are previously polished with sand paper to remove rust.

In the case of soldering thick plates,-

- either the joining surfaces of plates are 80 heated and-the'solder applied, orltihe eated so er, an

. faces are covered with pre thenpressad together, while the joining surfaces are be heated by a solderin per or iron. electric iron is pre used for the purpose.

Application-filed August 7, 1924. Serial Io. 780,878.

Metallic aluminium has a property1 of being easily oxidized by heating, and t erefore it is necessary that the soldering temperature must be as low as possible. It is also well known that at the heating parts of aluminium alloys, especially in such as duralumin, molecular constitution becomes brittle in high temperature. As the alumi. no-solder, according to this invention, has a meltin point far lower than that of the known kllldS as described, the solder is well suited for the purposes herein mentioned. The lead employed in this invention has the effect of increasing the malleability of the soldier, avoiding brittleness of the zinc therein, and due to this fact, very eflicient results are obtained.

Besides the characteristic properties of the alumino-solder as above described, it has excellent properties as follows:

Lead and cadmium in the solder serve to facilitate the soldering o erationby rendering the solder easily di usible. Said ingredients also act to retain the heat at the oints due to their low de of conductivity as compared with t at of metallic aluminium. Besides, cadmium serves to promote the fusibility of the solder by its reacting with the alloy of lead and tin.

It is well known that an alloy containing zinc and tin becomes brittle after a time due to the comparatively large c stalline construction, This alumino-sol er, however, has not such a defect owing to the presence of lead and cadmium therein.

The solder, made as above described, has solid and close molecular construction very strong strength, and is of a high fus'bility. Its fusing temperature is 230 G.-400 C. and as the content of'cadmium increases, the fusing temperature decreases. After soldering an aluminium alloy,(mainly duralumin) with the same or another aluminium alloy; metallic aluminium withmetallic or an aluminium alloy; or metallic aluminium with any other metal etc. using this solder, the soldered parts are never injured by chemioal action in contact with air and water. The operation of soldering can be carried out under far lower tem raturesthan usual andgjtherefom, the working is easler and the joint made is stronger than iscustomarily produced. c

What is claimed is: 1. Alumino-solder contalmng 20-70% of I10 zinc, 20-70% of tin, 5-35% of lead, 350% of cadmium, 15% of tin phosphide and 15% of magnesium, substantially as described, I

2. The method of making alumino-solder, which consists in heating a quantity of tin at a, temperature of 230 0., adding thereto a. quantity of lead and tin phosphide, heating the mixture at a temperature of 330 0.. adding a quantity of cadmium, zinc and magnesium, and continuing the heating of" the mixture at a temperature of 420 C. until said mixture is fused.

MURAJI TORII. 

